There has been much interest recently in the therapeutic benefits of antioxidants, including a possible protective role in preventing or delaying cognitive decline. This study describes the use of antioxidant supplements among 1,059 rural, noninstitutionalized elderly residents of southwestern Pennsylvania who are participants in the Monongahela Valley Independent Elders Survey. The data were collected during the survey's second wave of follow-up (1989–1991). The mean age of participants was 74.5 years (standard deviation 5.5), and 57.3% were women. Current use of nutritional supplements containing vitamin A, C, or E, β-carotene, zinc, or selenium was measured through self-report. Subjects were administered a battery of 15 neuropsychological tests measuring performance in several cognitive domains. Of the 1,059 persons, 342 (32.3%) were taking antioxidant supplements. Women and persons with higher levels of education were more often antioxidant users. Antioxidant use did not vary significantly by age, race, or income. In univariate analyses, antioxidant use was significantly and positively associated with performance on several cognitive tests. However, after adjustment for age, education, and sex, there were no significant differences in cognitive test performance between antioxidant users and nonusers. This study is one of only a few that have analyzed the relation between antioxidants and cognition in a community-based sample. After potentially confounding factors are accounted for, the results do not support the hypothesis that antioxidant supplement use is associated with cognitive function. Am J Epidemiol 1998; 148:38–44.